1. Field
The present general inventive concept herein relates to semiconductor devices, and more particularly, to a semiconductor device including a clock signal generation unit which receives a differential signal to generate a clock signal.
2. Description of the Related Art
To drive a semiconductor device, an internal clock signal (hereinafter referred to as a clock signal) may be generated by using an external clock signal (hereinafter referred to as a strobe signal) being transmitted from a controller to read received data according to the generated clock signal. Specifically, a differential signal may be used as the strobe signal to minimize electrical interference from external sources.
Using the differential signal as the strobe signal helps prevent external electrical interference, but has a disadvantage in that a received strobe signal cannot be read when levels of two signals constituting a differential signal are the same due to transmission errors. Furthermore, when a high impedance signal is transmitted as a strobe signal, a received strobe signal may not be able to normally be read. A technology of weakly pulling up/pulling down a strobe signal may be used in preparation for receiving a high impedance signal, but the weak pull-up/pull-down technology has a relatively slow reaction velocity and thereby is not suitable for a pull-up/pull-down of a high frequency signal.